1. Field of the Invention
The invention relates in general to a ball grid array formed on a printed circuit board, and more particularly, to a ball grid array having good ground shielding.
2. Description of the Related Art
To electrically connect a ball grid array (BGA) packaged chip to a printed circuit board, the printed circuit board must be provided with a ball grid array corresponding to the packaged chip. The ball grid array on the printed circuit board is formed by a plurality of solder balls, few of which are connected to ground so as to ground shield the remaining solder balls. However, an arrangement of a ball grid array on a printed circuit board is not necessarily regularly patterned. That is, a shape of the ball grid array as well as the number and positions of the grounded solder balls may vary along with different chips.
As described above, since a conventional arrangement of solder balls is not fixed to a regulated pattern, and solder balls may be scattered with a low density, thus, the usable area of the printed circuit board is often under-utilized. Further, a custom design of a ball grid array is unlikely to be repeatedly used, and human resources are required for verifying performance of a ball grid array.